The Wax Crystal Effect on the π-Stacking Dimerization of Asphaltenes in Wax-Doped Asphaltene Model

Despite wide attention to the laboratory investigation on the complex mixture of waxy crude oils to study the development of microstructures like bumble-bees this issue has received little attention from theoretical viewpoint, in general, and rigorous quantum calculations, in particular. With this motivation and, based on density functional theory (DFT) we study asphaltene dimerization in the presence of crystalizing wax paraffin. The typical n-paraffin selected is n-C11H24, and wax-doped asphaltene model is made by adding wax model on top of the optimized structures of asphaltene monomer and dimer. Quantitative evaluation of the strength of interactions between asphaltene unit sheets (in a dimer) in presence and absence of wax component, in one side, and investigation of the mutual interaction between asphaltene (monomer and dimer) and paraffin wax, on the other side, reveal that paraffin waxes not only do not reinforce the interaction between the asphaltene unit sheets, but also destabilize the complex (W-AA) compared to the W-A. This destabilization in interacting systems (asphaltene-asphaltene and also wax-asphaltene) decreases the possibility of the hypothesis that strong interaction between paraffin waxes and non-wax components, such as asphaltene, is responsible for the creation of bee

کلیدواژه ها:

Wax ، Asphaltene ، crystal effect